Upon reaching adulthood, foenaran nimbii can soar higher than any other creature in existence, spreading their cloud-like bodies over vast amounts of space. They can condense themselves into near-solid forms to be close to their magi if they wish, and their ability to control the weather and bring clouds into existence, or fetch clouds from far away, make them valuable and feared all at once. Some magi claim it is dangerous to allow them to use their abilities, as they may change the weather for the worse in unknown locations. Histories suggest these creatures were used as spies during the mage wars, as many old parchments and papers declare how important it is that secret meetings be held under a clear blue sky.

In Foenara, clouds over the grass forest may not be clouds at all, but the foenaran nimbii, a creature borne of water vapor and ancient magic. The details of their initial discovery, or perhaps creation, are lost in the mists of history, and much about their life cycle is unknown. It is equally uncertain why their eggs can only be found nestled in the long grass of Foenara. While the eggs of normal foenaran nimbii are not as valued as that of the king foenaran nimbii, Foenaran citizens are encouraged to find and hatch these eggs at all times. Despite people continuously hatching the eggs, the skies of Foenara do not get overrun with clouds. Some magi think these creatures have short lifespans, the creatures dissipating into mist as the years go on, while others think they travel, floating all around the world. Some magi even believe that every cloud in the world was once a nimbii, and they believe that the nimbii, born from the earliest volcanoes at the dawning of the world, are responsible for keeping the atmosphere of the world in place.